Numerical assessment of the seismic response of hillside buildings

Abstract

The use of hillsides for the construction of structures is problematic, mainly because of two conditions: the variation of the seismic response of the ground, due to the slope; and the modification in the structural configuration to account for the inclination at the base of the structure. These conditions have generated significant seismic damage in high slope areas in past earthquakes. This study seeks to evaluate the possible differences in the seismic response resulting from these two special conditions, evaluated in an uncoupled manner. For this purpose, a series of time-history analyses are performed using modified-by-topography seismic records on a group of structures with different base angles. The structures are first designed and evaluated in nonlinear response by pushover analysis. Greater variations in response are obtained as a result of the variation in the structural configuration (staggered) than as a result of the topographic effect, which, however, increases the aforementioned effects in both damage and displacement levels. The vertical accelerations induced by topography are detrimental to structural performance, with more damage (incursion into the inelastic range) being observed in the structures when these are considered in the analyses, as well as important differences in the axial load levels in the vertical elements.